Blake,
I think there are several factors that go into your voice change. If you started with a higher voice to begin with, it may take longer to change. Even among xy males, if you listen, men in their twenties and thirties generally have higher voices than older men.
Unfortuntely, the age at which the voice changes in puberty, were probably spent for you in an xx body, and that includes the larynx. Be aware of your voice when you talk and help train yourself to drop your voice an octave. Often, what you perceive as a noticeable change, may not be as noticeable to other people. F to Ms look younger than their chronological age and that may make people meeting you unsure of your gender. Try not to let the mistakes of others upset you too much. I've seen young xy men either during or after puberty that were misgendered.
Sam1234